Abstract:The isotopic effect on nuclear dynamics in Coulomb explosion for various initial vibrational states of H2+ and HD+ in intense laser (80 fs, 800 nm, I=6.8×1013 W/cm2) is theoretically investigated by numerically solving the time-dependent Schr?dinger equation. The calculated results confirm that the effect we discussed by paying close attention to the comparative analysis of peak locations in the nuclear kinetic-energy-release spectra largely depends on the selection of the initial vibrational states. Furthermore, it is the special isotope effect case about the vibrational state υ=5 that has been studied in depth. We also discuss the time-dependent spectrum at υ=7, which can reveal the difference in nuclear wavepacket motion between H2+ and HD+ in the time region in which charge-resonance enhanced ionization takes place.